Folding box



C. M. KELLER FOLDING BOX Nov. 10, 1953 2 Sheets-Sheet 1 Filed April 28, 1948 a a M n M M n n 2.

w a 2 z a; C. n

Cur o/w M Kali/e Nov. 10, 1953 Filed April 28, 1948 c. M. KELLIVER 2,658,660

FOLDING BOX 2 Sheets-Sheet 2 Patented Nov. 10, 1 953 UNITED STATES PATENT OFFICE FOLDING BOX Clifford M. Keller, Chicago, 111.

Application April 28, 1948, Serial No. 23,718

.3 Claims. 1

The present invention relates to improvements in folding boxes and a method and means for assembling same.

The present invention supplies the demand for a successful folding box which is self-securing and thus requires no string or cord or other separate fastening means, the construction and relationship being such that the box can be folded up from a flat blank at the point of use, with the contents enclosed and will remain closed until deliberately opened. The box is ideally adapted for use as a laundry box, suit box or the like.

An important object of the present invention is to provide a folding box that can be used at the point of use and there quickly and easily folded up from a flat blank into a self-securing package, utilizing much the same steps as are involved in folding a package from a flat piece of paper but which must be then held together by means of twine or cord or other fastening medium.

Another object of the invention is to provide a folding box having a novel arrangement of self-securing tabs.

A further object of the invention is to provide a novel method of packaging with a folding box which is susceptible of wrap-type use.

Still another object of the invention is to provide improved means for assembling'and loading a self-securing folding box.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying two sheets of drawings in which:

Figure 1 is a perspective view of a folding box embodying features of the present invention in fully assembled condition;

Figure 2 is a plan view of the blank for the box of Fig. 1;

Figure .3 is a more or less schematic view showing certain successive steps in the assembly of the box of Fig. 1, and apparatus for assistin in the loading and assembly;

Figure 4 is a similar more or less schematic view showing a further step in the assembly of the box;

Figure 5 is an enlarged fragmentary open end perspective view of the box showing the same as it appears when ready for final closing assembly, but with the upper flap bent up out of its normal plane for clarity of illustration;

Figure 6 is another fragmentary end perspec- Fi ure '7 is an enlarged fragmentary upper end corner view showing the interlock slit and tab structure in which the locking tab at the same end of the box is received;

Figure 8 is a fragmentary enlarged vertical sectional view taken substantially on the line VIII-VIH of Fig. '7 and showing one of the interlock flanges or tabs;

Figure 9 is an enlarged fragmentary vertical sectional detail view substantially like Fig. 8 but showing the locking tab in partially assembled relation in the interlock slit and as it passes over the interlock tab;

Figure 10 is a fragmentary top plan view of the same end of the box showing the securing tab in securing position;

Figure 11 is a perspective view of a fully assembled modified form of the box embodying a two piece construction;

Figure 12 is a plan view of the bottom or tray portion for the two piece box of Fig. 11; and

Figure 13 is a plan view of the blank for the cover portion of the two .piece box of Fig. 11.

A unique feature of the present box resides in the fact that it can be assembled from a flat blank to envelop a load or contents with much the same motions involved in wrapping a package with a blank piece of paper. To this end, a box l5 (Fig. 1) is adapted to be assembled from a blank 16 as shown in Fig. 2. The blank comprises a bottom wall panel I! scored opposite side wall panels i8 and I9, a top wall panel 20, an end terminal reinforcing flap panel 2! on the wall panel I8, and a locking tab 22, the several panels and tab being defined by appropriate scormg.

As thus far described, the box blank I6 is adapted to be folded up into a tubular assembly. This is adapted to be accomplished as best seen in Figs. 3 and 4 by pressing the bottom panel ll down into an assembly fixture 23 of substantially U-shape cross section having a base structure 24 of preferably approximately the same area as the bottom panel I1, and spaced parallel upstanding side flanges 25 by which as the base panel is pressed down against'the base 24 of the fixture the side wall panels 18 and I9 are wiped up into perpendicular relation to the bottom panels ll. As seen in Fig. 3, the blank 86 shown in dash outline is adapted to be laid upon the upper edges of the flanges 25 of the assembly fixture and the bottom panel I! then pushed down into the fixture to attain a partially assembled.

relationship of the box blank substantially as indicated in full outline. In this condition the cover panel 20 may be bent back out of the way as indicated and the reinforcing flap panel 2| may remain in the plane of the attached side wall panel i8. Thereupon the contents which it is desired to load into the box may be placed into the generally U-shape trough provided by the bottom panel I? and the upstanding side wall panels l8 and I9. This is particularly advantageous for such purposes as boxing fresh laundry preparatory to delivery thereof.

After the contents have been loaded into the partially assembled box trough, the cover panel 20 is swung over toward closing position, the reinforcing flap panel 2| is bent inwardly, the cover panel is brought down upon'the inturned reinforcing panel 2|, and the locking tab 22 is inserted into an interlock slit 2? provided therefor at the juncture of the side wall panel i8 and the flap panel 2|. This completes the basic tube of the completed box, substantially as shown in Fig. 4.

The final step in closing the box comprises bending into overlapping relation end flap panels 28 and 29 on the side wall panels l3 and i9 respectively from the full line position as shown in Fig. to the dash line position, then folding down end flap panels 30 on the top panel 29, and folding up end panels 3| on the bottom panel I I.

As an incident to folding the end panels 3| into final position, locking tab 32 thereon are inserted into respective locking slits 33 formed at the juncture of the respective end panels 30 with the top panel 26.

By preference the end panels 28 and 29 are formed with interlock tongue and slot structure to enable securing the same together as a preliminary assembly step in the folding up of the box where it is desired to provide a tray in which the contents may be handled and moved about with the box prior to finally closing the box. This may become desirable in laundry practice, for example, where it is found that part of an order is not in proper condition and must be reprocessed, or is missing or for any other reason the box may not properly be finally closed. To this end, the end panels 28 are formed with generally T-shape integrally struck out respective locking tongues 34 which are adapted to be inserted when desired into interlocking slits 35 provided therfor in the end flap panels 29. The arrangement and relationship of the locking tongues or tabs 34 and the slits 35 is such that latterly extending interlock ears 3'! on the respective tabs 34 will engage behind interlock tabs 38 provided at the ends of the interlock slit 35.

In the final assembly, the end panel 39 overlaps the overlapped end panels or flaps 2B and 29 and holds them in place, and the end panel or flap 3| in turn holds the end panel or flap 30 in place. This relationship is shown in Figs. 1 and 6.

In order to effect an efficiently locked condition of the locking tab 32 in the interlock slit 33 and in a manner which will retain the closed condition of the box until the locking tab 32 is deliberately withdrawn from the slit 33, appropriate interlocking structure is provided on the tab 32 and in association with the slit 33. For this purpose the locking tab 32 is provided at it base with a pair of identical inwardly extending notches 39 whereby the tab is shaped to provide a pair of oppositely extending ears. The end portions of the slit 33 are preferably cut on an arcuate line 40 inwardly into the panel 20 and merge with offset, aligned, substantially parallel terminal cuts 4| to define interlock tabs 42. While the box blank is in flat condition, the tabs 42 remain flat in the plane of the blank. However, since the proximate base ends or sides of the tabs 42 join the adjacent margin of the contiguous flap through the score line between the flap and the top panel 20, the tabs 42 are stressed to turn upwardly and stand out of the plane of the top panel 20, as an incident to bending down of the flap 30 during assembly of the box. This condition has been depicted in Figs. 7, 8 and 10, as accurately as practicable in a line drawing to show what actually appears in practice.

The proximate sides of the interlock tab 42,

that is the sides which join the flap 30, are spaced apart approximately the same distance as the spacing between the inner ends of the notches 39 at the base of the tab 32. On the other hand, the remote ends of the offset aligned cuts 4| which result in the cutting of the tabs 42 are spaced apart at least the same distance as the maximum width of the tab 32 and preferably slightly farther to afford ease in assembling the tab 32. Hence, when the locking tab 32 is introduced into the slit 33 its preferably rounded off leading end will enter between the interlock tabs 42 and then the following portion of the locking tab will ride over the interlock tabs, depressing. the latter substantially as seen in Fig. 9 until the. lockin tab 32 has entered fully into the slit and the interlock tabs 42 spring up of their own inherent resiliency within the interlock notches 39. This places the interlock tabs 42 in intercepting relation to shoulders 43 on the locking tab 32 at the forward sides of the notches 39 and effects an interlocking relation with the tab 32 to resist Withdrawal thereof. As a result, the flap 3|: is held by the interlock condition of the tab 32: and the interlock tabs 42 in position to maintain the overlapped flap assembly at the end of the box in the assembled condition until the tab 32 is deliberately withdrawn with sufficient force to destroy one or both of the interlock tabs 42 in. the escape of the interlock shoulders 43 of the locking tab past the interlocking tabs 42.

Of considerable assistance in effecting quick, easy assembly of the locking tab 32 in the slit 33 is the tongue which, in effect, overlies the adjacent edge of the bent down flap 30 at the upper side of the slit 33 and intervening between the interlock tabs 42 as a result of the arcuate cuts 48, and identified at 44.

In order to avoid objectionable protruding corners that might get caught on adjacent objects and under certain conditions might even tend accidently to pull the flap 3| open, the flap 3| is preferably cut on a taper from its lower corners to the base of the locking tab 32.

While for convenience in illustration, one of the end portions of the box has been selected and a detailed description afforded of the interlocking nature of the locking tab 32 and the interlock tabs 42, it should be understood that substantially the same interlocking construction is provided with respect to the side locking tab 22 and the interlock slit 21. The locking tab 22 is provided at the base portion thereof with inwardly extending interlock slots or notches 45 defined at their forward sides by interlock shoulders 41 which in assembly within the interlock slit 2'! engage forward or inwardly of interlock tabs 48 which in all essential respects are the same as the interlock tabs 42 described hereinabove.

games From the foregoing. itwill beapparen't that the box- I5 is adapted to be foldedup into assembled condition quite-speedily with the contents to be contained therein and that the operations involved in assembling the .box rather closely follow the same steps as. involved in folding up a paper wrapp r about a package, with the salient difference that the assembled condition of the box is maintained more or less permanently as a result of the side locking tab 22 and the interlock tabs 48 and the end lockingtabs32 and the interlock tabs 42. cooperating automatically to maintain the assembled condition.

Theassembly of overlapping flaps at the ends of the box affords an especiallysturdy end struct me which is capable of withstanding relatively heavy loads such as imposed where the boxes in loaded: condition are piled one on the other. This sturdy end structure is also highly desirable to withstand the thrusts and general abuse incident tohandling on an assembly line production basis or where the boxes must travel down a chute to a loading platform and thus pile u end to end one against the other or strike against one another rather forcefully, and the like.

It will also be apparent that the box is readily susceptible of manufacture in a large variety of sizes to meet various practical requirements. Where size demands, a plurality of locking tabs and associated interlock tabs can be provided along any edge or joint as desired. The box I5, for example, selected for illustration is of proportions that have been found especially desirable as laundry boxes.

Where the proportions demanded in the box or other requirements demand a two piece box, that is a box having a tray portion and a lid portion which are separate until finally assembled together, a two piece box 5|] as shown in Fig. 11 may be utilized. In Fig. 12 is shown a blank 5| from which the tray portion of the box is set up, and Fig. 13 shows a cover blank 52 for the box.

The tray blank 5| comprises a bottom panel 53, end panels 54 and terminal flap panels 55 on the side panels. The base panel 53 has generally triangular end flaps 51 which terminate in interlock tabs 58 having all of the same characteristics as the locking tabs 32 previously described. The side panels 54 have respective end flaps 59. All of the panels and flaps are, of course, appropriately delineated by appropriate scoring.

The cover blank 52 comprises a cover panel 60 which is of substantially the same proportions as the bottom panel 53 and has end flaps 6| delineated by appropriate parallel scoring. At its remaining edges, the panel 60 has centered, oppositely extending interlock tabs 62 which correspond to the interlock tab 22 previously described.

In assembling the blanks 5| and 52 to form the completed box 50, the tray panel 5| has the side panels 54 thereof bent up into perpendicular relation to the base panel 53 and the end flaps 59 are then bent inwardly and the end flaps 51 thereafter bent up to retain the end flaps 59. The terminal panel flaps 55 are also bent inwardly perpendicular to the side panels 54. Thereupon the contents having been deposited in the tray thus formed, the cover blank 52 is manipulated to bend the end panels 6| perpendicular to the cover panel 60 and the end panels 6| are then interposed between the flaps 59 and the respective companion flaps 51 of the tray. The locking tabs 58 are then inserted into interlock relation in respective interlock slits 63 provided therefor at the junctures of the respective end Panels. 6| with the top panel 60, and the locking tabs 62' are inserted into respective locking slits 64 provided therefor at the junctures of the terminal panel flaps 55 and the side panels 54, to complete the assembly of the box. It will be understood, of course, that the precise order of interlocking of the locking tabs in their slits as just detailed need not be followed precisely but that any other preferred order of interengagement of the locking tabs in their respective interlock slits may be adopted as preferred, the end result being the same.

Each of the, locking tabs 58 has adjacent the base thereof similar inwardly extending interlock notches 64 interengageable in assembly with interlock tabs 65 at the ends of the respective slits 63. The interlock tabs 62 have interlock notches 61 which in assembly are adapted to engage inwardly of and interlockingly with respective interlock tabs 58 at the ends of interlock slots, 64.

The box 5|], similarly as the box I5, is, in fully assembled relation, self-retaining, requiring no additional fastening device. Upon deliberate opening of the box destruction of the interlock tabs at the points where the locking tabs are withdrawn is the general result. Thus boxes of this type, either of the type. of the box, L5 or the type of the box 50 are of acne time. use nature.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

1. In a folding box structure, a part having a locking tab thereon, said tab having similar oppositely opening base notches therein, and another part comprising a pair of panels bent angularly to one another and having an interlock slit at the juncture thereof for receiving said locking tab, the end portions of said slit being angularly ofi'set relative to the intervening portion of the slit and away from the juncture to define a spaced pair of interlock tabs having their proximate edges spaced approximately the same distance as the width of the neck intervening between said notches and having additional edges disposed angularly relative to said proximate edges and directed away from said juncture, said interlock tabs normally being stressed to project angularly out of the general plane of the panel from which derived, said locking tab being insertable in said slit and acting during insertion to depress said interlock tabs to pass thereby, said interlock tabs snapping up of their own inherent resiliency into said interlock notches upon registration of the latter with the interlock tabs, whereby said additional edges oppose oppositely directed edges on the locking tab to restrain withdrawal of the locking tab from the slit.

2. In a folding box structure, a portion comprising panels bendable along a score line into angular relation, the juncture bend having a slit therein extending parallel therealong, the opposite ends of said slit having angular extension cuts of angular delineation extending into one of said panels and with the angularity of each of said cuts extending generally away from the juncture bend adjacent to the respective proximate ends of the slit and then at their terminal portions extending in generally parallel offset relation to the bend juncture, the portions of said one panel intervening between said cuts and said bend line defining interlock tabs which are stressed by bending of said panels at said juncture bend to project angularly out of the plane of said one panel, and another portion having a tongue-like locking tab formed with oppositely extending ears, the overall width of said tab at said ears being no greater than the combined length of said slit and said extension cuts, said locking tab being insertable into said slit and with the ears depressing said interlock tabs until the ears are fully inserted within the slit and the interlock tabs snap up behind the ears to block withdrawal of the ears from the slit and thereby retain the locking tab assembled therein.

3. In a box structure made of flexible material, a panel having a tab-receiving slit therein, and a portion cooperable with said panel and having thereon a locking tab insertable into said slit from one side of the slit into face to face relation to the panel, said tab having oppositely directed locking ears the overall lateral extent of which is no greater than the total length of said slit, the extremities of the slit being oifset from the main intermediate portion of the slit toward the opposite side from which the locking tab approaches the slit during assembly, said terminal portions of the slit being connected by respective 8 angular portions to the main body portion of the slit and thereby defining at the end portions of the slit respective interlock tabs each of which has an edge portion directed generally toward the opposite interlock tab and an edge portion directed in the direction of movement of said locking tab during assembly of the locking tab into the slit, said interlock tabs being resiliently flexible upon engagement by said locking tab ears during assembly of the locking tab into the slit to clear passage of the locking tab into the slit and being springable into interlocking relation b hind said locking tab ears after the locking tab ears have been fully inserted into the slit past said interlock tabs so as to block Withdrawal of the locking tab from the slit.

CLIFFORD M. KELLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,081,981 Palmer Dec. 23, 1913 1,141,489 Richardson June 1, 1915 1,198,435 Gebhart Sept. 19, 1916 2,190,433 Palmer Feb. 13, 1940 2,399,537 Belden Apr. 30, 1946 2,481,288 Cage Sept. 6, 1949 

